Incandescent electric lamp.



D. J. O'BRIEN. INGANDESGENT ELECTRIC LAMP. APPLICATION FILED JUNI; 14,1905.

1,1 1 7 Patented Sept. &, 1914, I Fig". 1- 4 /B v 7 s\ 9 W/T/VE55E5 IN VEA, 717R.

' several letters of a sign.

UNITED STATES PATENT @FFICE.

DENNIS JOSEPH OBRIEN, 013 SAN FRANCISCO, CALIFORNIA, ASSIGNOR, BY MESNE ASSIGNMENTS, T0 STRAIGHT FILAMENT LAMP COMPANY, A CORPORATION OF NEW YORK.

INCANDESCENT ELECTRIC LAMP.

Specification of Iletters Patent.

Patented Sept. 8, 19 14.

Application filed June 14, 1905. Serial No. 265,276.

ifornia, have invented a new and useful lnr' provemcnt in Incandescent Electric. Lamps, of which the following is a specification, reference being had therein to the accompanying drawing.

This invention has for its object both to prolong the life and to increase the lightgiving capacity of incandescent electric lamps.

It is a well-established fact that the standard grades of these lamps average but a little over 265 hours of life, and the poorer kind proportionately less, some being quite short-lived and becoming extinct or passing out of the domain of usefulness after a service of scant duration. With the best lamps of any make, the time comes when their filament gets so attenuated through usage and,

offers such resistanceto the passage of the electric current as to increase the waste thereof beyond reasonable limits and render it advisable to replace them by new ones rather than maintain them at a greater ex pense. This failure of the filament, whether entirely consumed or worn out, is the principal cause of the lamp being unfitted for use and then treated as totally-worthless, that is, as an object to throw away. Because the filament fails, though representing only a fraction of the cost of manufacture, the whole lamp ordinarily goes to the scrap heap, notwithstanding that vast sums of money have been expended in the .endeavor of finding a means to avoid such waste, and save an otherwise good lamp by changing or renewing its filament. Another fact, worthy of full consideration in this matter, is that filament-lamps, like other lighting devices,

.sired without its accustomed light or its complement of lights, for instance where the failing lamp or lamps formed part of a line or gnonpaas in a display-window or in the Besides, there are numerous occasions, during festival nights or on evenings specially devoted to business,

when a liberal user of electricity would Welcome the possibility of heightening thecandle-power of his or her lamps and not mind the extra expense in current, could it be done with the supply of lamps ordinarily employed, that is to say, without incurring the additional expenditure of a special installation for the purpose and using more lamps than are lighted at any other time.

For the above reasons, it is eminently desirable to havean incandescent electric lamp that will be longer-lived than any lamp of the same class heretofore made; one also Whose capability to give light will not be permanently impaired or destroyed by the mere attenuation or burning out of a filament with which it is placed into circuit; and one capable further of yielding a high, divisible candle-power, the units whereof may be utilized singly or cumulatively or conjointly in divers combinations. The present invention produces such a lamp by providing it with a phirality of filaments capable of use together or in rotation. Two, three, or more filaments are placed in the one tube or bulb, and they are set and arranged so that each of them can be connected in the electric circuit separately and lighted alone, or any two, or any three or more, or all of them can be combined in the circuit and caused to burn collectively. By using the filaments successively one at a time, the life of the lamp is naturally lengthened as many times as there are required, in order to keep the lamp burning, to change its position or connect in the circuit, as the case may call for, the seeone, third, fourth, or other of its reserved filaments, and the same lamp will continue to give light till each and every one. ofthem has been consumed. On the other hand, when a more intense light than the ordinary is desired, the filaments can be brought into the circuit in twos and threcsand so on according to the candle-power wanted, in which case, of course, none of the lamps that may thus be used will last as long as it would by consuming a single filament at a time and the expense will be higher, but the candle'power will be twofold, threefold, or

minors in the glass analogously to and does the same the trident is shown as runnin straight to its own end of the tube, coincidentlywith the point of closure at that end, which ar 'rangement is suitable, but this can be changed if desired, since thereis nothing to preclude bending the anchor iso as'to lead it in some other direction, it being made of same Wire as the anchor 3. l The trident itself, it is understood, would be changed to a t vo-pronged or toy arfourpronged or multi-pronged anchor inlihe ratio as the number of filamentsinclcsed in the tube and having the common terminal would be diminished or augmented.

To properly adapt the above-described 2o tube-lamp to the electric circuit, metallic caps 7 are cemented over the glands 6, and the outer ends or theanchors 3 and i are brought out sufficiently to pass through and be soldered upon them,'as indicated at 8, Figs. 1, 2' and 3. These caps are provided each with a pair of marginal lugs 9, extend ing from opposite sides and folded back and up to fit snugly between. or Within spatular contact-pieces 10 or 11, secured in sockets 12 and projecting more. or less out of the same. I The lamp may be held to its sockets. by any suitable means. for instance, with the aid or forked holders and light spiral springs, as suggested at 13 and 14, Fig. 2. The lugged caps,.it will be noted, are peculiarly well adapted to effect good electric contacts and prevent undue concentration of heat'at any single point.

The lighting of the filamentssuccessively, 40 one after another, requires no explanation. It is patent that a partial rotation of the tube-lamp Within or relatively to its holders (one-third revolution in the illustration given) .will each time bring into action a diilcrent filament, whether it be provided with terminals entirely separate irom the others, as in Fig. l, or with one separate and one common terminal, as in 2. As one filament is consumed, the lamp can be revolved to the next contact points upon its sides, or upon one of its sides and-one of its ends, and a fresh filament placed in circuit, which when burned out will in turn be substituted by another, and still another, according to the number of filaments comprised in the lamp. The maximum duration of the lam-p may be attained by using it in this manner, and if the glass envelop be properly exhausted of air, and freed from so other gases as Well, it Will not fail to transayanchors, while its prongs respectively re 1 p. ace their shorter members. The stem oi unit-such light as any or the filaments isv able to emit under normal conditions.

.A connector is employed When it is desired to place two or more or all or; the filaments together in circuit; l t/suitable form of such connector for the filaments of the 1 tube-lamp isshown-in edge and perspective views respectively in Figs. 3' and i, Where the same is designated by the reference numberflfi: As there represented, this form of connector consists 'of' a light band of flexiblemetal, ha ing a hole it, through which is passed theflugged cap to be used for making. the electric contact, and pockets 17,

which theother, caps at the same end of the lamp are adapted to enter. When the several caps corresponding with the separate terminals atone end or" the lamp are thus connected, and the lamp is socketed, as in Fi 2 for example, all the filaments are lighted together and burn at the same time. But if it is desired to light only two out of three or lessthanthe' Whole number or filaments, then :the connector can be bent back, as indicated'by dotted lines in Fig. 3, and such filament or filaments as. onejdoes not Want to use will be cut out. The amount of light can easilyjbe regulated in this man ner, and the lamp made of 16, 32 or 48, candle-poWer and oveigat option, as circumstances may require or suggest.

What lfclaim, and desire to secure by Letters Patentofthe United. States, isv 1. An incandescent electric lamp comprising a glass tube, a plurality of filaments secured in outwardly-projecting glands of the tube, metallic caps over said anchors and glands, means for placing the caps pertaining to one filament in the electric circuit, and a flexible metallic band capable of connecting two or more filaments through their respective caps at one end or the tube. 2. "An incandescent electric lamp comprising a glass tube, a plurality. of filaments placed ofi center and held in parallelism therein, a plurality of peripheral contacts located opposite-the ends of said filaments, anchors connecting said filaments With said contacts, and a flexible connector adapted to encircle one series of contacts at either end of said tube and place any one or all of the contacts of the series in the electric circuit. In testimony whereof I ailix my signature in presence of two Witnesses- DENNIS JOSE?H DBRIEN.

Witnesses A. H. MARIE, HENRY P. 'lnrooo'.

95 therein, metallic anchors for said filaments v v 

